1. Field of the Invention
The present invention relates to ester-containing polyether polyols and to the use thereof in the preparation of urethane compositions. More particularly, the invention relates to ester-containing polyether polyols having bromine atoms chemically bound therein and to the use thereof in the preparation of flame-retardant polyurethane foams.
2. Description of the Prior Art
It has become increasingly important to impart flame-resistant properties to polyurethane plastics. This is particularly true where cellular polyurethanes are used, for example, as insulation, and to prevent the risk of fire in the daily use of other items. Numerous methods are known for imparting fire-resistant properties to polyurethane plastics. For example, in the production of the cellular polyurethanes, one may use halogenated compounds or derivatives of acids of phosphorus as the active hydrogen-containing component, and thus impart flame-resistance. It is also possible to use compounds of antimony or boron.
Certain ester-containing polyols having halogens atoms chemically bound therein have also been demonstrated to be effective as fire-retardants in polyurethane compositions. For example, U.S. Pat. No. 3,585,185, there are disclosed ester-containing polyols prepared by the reaction of alkylene oxide adducts of organic compounds having at least two active hydrogen atoms with a halogen-containing organic acid anhydride and an alkylene oxide. However, these halogen-containing polyols require relatively high percentages of halogen in order to be effective.
It is an object of the present invention to provide brominated ester-containing polyether polyols which impart flame-resistant properties to polyurethane compositions at relatively low bromine concentrations. It is a further object of the present invention to provide polyurethane compositions useful in the preparation of foams, adhesives, binders, laminates and coatings. These, and other objects of the present invention, will be apparent from the specification and examples which follow.